Over time, valve stem seals lose effectiveness gradually and oil leaks into the combustion chambers, this oil gets burned during the power stroke producing hydrocarbons that exit from the tail pipe. Each valve is located on the cylinder head and is held firmly against its seat by a spring that presses it against the valve seat and the spring retainer and is secured to the valve stem by locks (keepers). In the past, different procedures or methods were use in order to replace valve stem seals or springs: one of the most common but time consuming procedures involves the removal of the cylinder head and using a C-clamp type spring compressor.
In one method and still the most preferred, the cylinder is pressurized with air in order to hold the valves, however, the disadvantage is the set up of the tool that permits the valve spring compressor to move from one valve spring to the other. It is also a time consuming method, and another disadvantage is the problem of firmly holding the tools in place that sometimes can result in injuries to the technician.
Another method was the use of a spring compressor tool that hooks onto the spring coil and compresses it by a screw type mechanism that is set onto the valve spring retainer. The disadvantage is that this tool only fits in few type cylinder head design.
There is still an existing need to provide an effective way for removal and installation of valve springs for the replacement of valve stem seals or the spring itself, by reducing the time and physical effort for the technicians, but also a safety method for the accomplishment of this special task in order to help reduce the amount of hydrocarbons released from the tail pipe to the atmosphere.